<i>Salmonella</i> Typhi Stool Shedding by Patients With Enteric Fever and Asymptomatic Chronic Carriers in an Endemic Urban Setting
Farhana Khanam, Thomas C. Darton, James Meiring, Protup Kumer Sarker, Prasanta Kumar Biswas, Md Amirul Islam Bhuiyan, Nazmul Hasan Rajib, Susan Tonks, Andrew J. Pollard, John D. Clemens, Firdausi Qadri
Abstract
The burden of Salmonella enterica serotype Typhi (S. Typhi) shedding in stool and its contribution to transmission in endemic settings is unknown. During passive surveillance S. Typhi shedding was seen during convalescence in 332 bacteremic patient with typhoid, although none persisted at 1-year follow-up. Anti-virulence capsule (Vi)-immunoglobulin (Ig) G titers were measured in age-stratified cohort of serosurveillance participants. Systematic stool sampling of 303 participants with high anti-Vi-IgG titers identified 1 asymptomatic carrier with shedding. These findings suggest that ongoing S. Typhi transmission in this setting is more likely to occur from acute convalescent cases, although better approaches are needed to identify true chronic carriers in the community to enable typhoid elimination.